Answer:
14 inches
Explanation:
In the above question, the perimeter formula is given as:
P = 2L + 2W
We are asked to rewrite the formula to solve for L.
This means to make L the subject of the formula
P = 2L + 2W
2L = P - 2W
Divide both sides by 2
L = P - 2W/2
We are to use the above formula to find the length of a rectangle whose width is 7 inches and perimeter is 42 inches.
P = Perimeter
L = Length
W = Width
L = P - 2W/2
L = 42 - 2(7)/2
L = 42 - 14/2
L = 28/2
L = 14 inches
Therefore, the length of the rectangle = 14 inches